The key question is what kind of soil do you have? If you have a medium to heavy soil anytime in the autumn would do. If, however you have a light, sandy soil like mine wait until late winter as it will just wash down. You can loosely fork it in or dig it in a bit. Beware of the chickweed! I get loads of it from horse manure but yours may be different depending on what the horses have to eat.

I spread it over the soil. I do this about now. I actually want the manure "washed" by the rain so that come the spring I'm left with a product that "stirs" in nicely with my top soil and any chemicals have disappeared. It helps create a fertile top few inches exactly where my veg need it. Over the years I have created a very good rich soil this way.

Im a no dig gardener except for the runner bean trench. For me, digging in compost, manure, etc., destroys fhe structure of the soil and deposits the manure too deep for the plants ro access it.

Agree about the chickweed daydaisy. This year's been the worst so far for me. Mind you, its easy to pull up of you see it.

I do the same as chicky. Just put some down on the new beds I've created as I won't plant them till spring. It was previously just a piece of rather poor grass. I stripped that off and then added some compost and soil and topped with manure.